Ispitivanje inflamatornog efekta hemijsko-mehaničke metode retrakcije gingive pri izradi fiksnih protetičkih nadoknada

The research started from the assumption that the chemical - mechanical retraction procedure, widely used for making of fixed prosthetic restorations, can lead to damage to the periodontal tissue, primarily to the inflammation of the gingiva. The chemical - mechanical method involves the use a retraction cord soaked in fluid - usually an astringent. The combination of mechanical pressure and chemical action on the gum tissue results in optimal expansion of the gingival sulcus and better control of the secretion of fluid in it, which enables accurate imprinting. The aim of the study was to investigate clinical parameters (gingival index and bleeding index) and salivary concentrations of proinflammatory cytokines (Tumor necrosis factor α, Monocyte Chemoattractant Protein 1, Interleukin 6 and Immunoglobulin A), as well as cytomorphometric analysis of gingival epithelial cells (nucleus surface, circumference of the nucleus, circularity, Feret's diameter, optical density, roundness, and solidity) before and after the chemical-mechanical retraction procedure. The retraction agents used were solutions of aluminum chloride and ferisulfate, and the subjects were divided into two groups depending on whether the procedure was performed on brushed or non-brushed teeth. The results of the study showed that the chemical - mechanical retraction method leads to a statistically significant increase in the values of the gingival index, the bleeding index and salivary concentration of proinflammatory cytokines, which indicates its inflammatory potential. The test values decreased over time, which is evidence of the reversibility of the inflammatory changes that have occurred. The obtained values depended on the retraction agent used, with a stronger inflammatory effect of the ferrisulfate solution. The group of the subjects with prepared teeth had higher values of the examined parameters. The chemical - mechanical retraction procedure caused changes in all cytomorphometric parameters of gingival epithelial cells. The surface area and circumference of the gingival epithelial cell nuclei were larger after retraction, which could be considered as a sign of gingival inflammation. A combination of clinical study and laboratory testing of the potential inflammatory effect of gingival retraction agents has yielded relevant findings applicable in dental practice in order to optimize therapeutic effects with minimal risk of iatrogenic damage

THERAPEUTIC ALTERNATIVES OF NATURAL COMPOUNDS IN TREATMENT OF CANDIDA-ASSOCIATED DENTURE STOMATITIS

Denture stomatitis is a common inflammatory reaction affecting denture wearers, multifactorial etiology, which is usually associated with Candida species, particularly Candida albicans. The treatment of Candida-associated denture stomatitis (CADS) is difficult and complex due to its multifactorial etiology, common recurrences, as well as the lack of antifungal drug efficacy. This review aims to critically discuss several key factors affecting adhesion and biofilm formation of Candida species on acrylic surface, as well as the use of herbs, proposed as an alternative in the treatment of CADS. Many factors affect adhesion and biofilm formation of Candida spp. on acrylic surfaces, such as surface roughness of the inner surface of the prosthesis, salivary pellicle, hydrophobic and electrostatic interactions. Having in mind that denture stomatitis is a common disease in total denture wearer, that it is most common in fungal etiology and that biofilm development increases yeast resistance, application of non-synthetic, completely natural substances, such as essential oils and extracts, may be suggested as a promising alternative for treatment of CADS

Biofilm formation on dental materials

Introduction: Dental materials play a role of morphological and functional substituent of the oral environment and they are expected to perform their function without causing adverse effects. A biofilm is formed on the surface of dental materials, as well as on other oral tissues. Considering that dental materials due to their structure, in most cases, allow accumulation of food residues and infectious content, a comparative review of possible consequences and the way of their prevention is of great importance. The aim of this manuscript was the analysis of biofilm formation on different dental materials surfaces based on published investigations and literature data. Knowing the structure of dental materials and their behavior in oral environment is a base for proper setting of indication for their use. The simplest way to control biofilm formation on materials is good oral hygiene and maintaining dentures. Conclusion: The formation of biofilm in dental materials lead to development of same diseases of oral cavity. The simplest way to control the development of biofilm is to maintain a ligh lovel of oral higiene

Analiza ivičnog pripoja kompozitnih smola za gleđ skening-elektronskom mikroskopijom nakon primene standardne i postepene tehnike fotopolimerizacije

Introduction Bonding between composite and hard dental tissue is most commonly assessed by measuring bonding strength or absence of marginal gap along the restoration interface. Marginal index (MI) is a significant indicator of the efficiency of the bond between material and dental tissue because it also shows the values of width and length of marginal gap. Objective The aim of this investigation was to estimate quantitative and qualitative features of the bond between composite resin and enamel and to determine the values of MI in enamel after application of two techniques of photopolymerization with two composite systems. Methods Forty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to enamel. Adhesion to enamel was achieved by Adper Single Bond 2 - ASB (3M ESPE), or by Adper Easy One - AEO (3M ESPE). Photopolymerization of Filtek Ultimate - FU (3M ESPE) was performed using constant halogen light (HIP) or soft start program (SOF). Results Quantitative and qualitative analysis, showed better mikromorphological bonding with SOF photopolymerization and ASB/FU composite system. Differences in MI between different photopolymerization techniques (HIP: 0.6707; SOF: 0.2395) were statistically significant (p lt 0.001), as well as differences between the composite systems (ASB/FU: 0.0470; AEO/ FU: 0.8651) (p lt 0.001) by two-way ANOVA test. Conclusion Better marginal adaptation of composite to enamel was obtained with SOF photopolymerization in both composite systems.Uvod Kvalitet veze kompozita za tvrda zubna tkiva se najčešće procenjuje jačinom vezivanja ili izostankom marginalne pukotine po obodu restauracija. Marginalni indeks (MI) je važan pokazatelj efikasnosti pripoja materijala za zubna tkiva jer istovremeno pokazuje vrednosti i širine i dužine marginalne pukotine. Cilj rada Cilj rada je bio da se kvantitativno i kvalitativno proceni veza kompozitnih materijala za gleđ i utvrde vrednosti MI u gleđi nakon primene dve tehnike svetlosne polimerizacije i dva kompozitna sistema. Metode rada Na ekstrahovanim zubima je restaurisano 40 kaviteta pete klase za analizu pripoja kompozita za gleđ skening- elektronskom mikroskopijom (SEM). Adhezija za gleđ je obezbeđivana primenom Adper Single Bond 2 - ASB (3M ESPE), odnosno primenom Adper Easy One - AEO (3M ESPE). Svetlosna polimerizacija kompozitnog materijala (Filtek Ultimate - FU; 3M ESPE) vršena je standardnim halogenim svetlom (HIP) ili tzv. soft start programom (SOF). Rezultati Kvantitativna i kvalitativna analiza je pokazala bolje mikromorfološko vezivanje kompozita za gleđ kod SOF osvetljavanja i ASB/FU kompozitnog sistema. Na osnovu dvosmernog ANOVA testa, razlike u vrednosti MI između različitih svetlosnopolimerizujućih tehnika (HIP: 0,6707 i SOF: 0,2395) bile su statistički značajne (p lt 0,001), kao i razlike između kompozitnih sistema (ASB/FU: 0,0470 i AEO/FU: 0,8651; p lt 0,001). Zaključak Bolji marginalni pripoj kompozita za gleđ obezbeđen je primenom SOF osvetljavanja kod oba kompozitna sistema

Analysis of cyclic fatigue resistance of ProTaper Universal and ProTaper Next rotary instruments

Introduction Root canal preparation is one of the most important active phases in the treatment of infected and noninfected teeth. Nickel-titanium (NiTi) instruments are increasingly used in endodontic therapy due to their superior properties compared to those made of stainless steel. The aim of this research was to perform an analysis and comparison of cyclic fatigue in ProTaper Universal and ProTaper Next rotary NiTi instruments in full rotation in simulated canals. Material and methods Twelve ProTaper Next and twelve ProTaper Universal instruments were analyzed in the study. The instruments were tested in an artificial canal stuffed in a metal block at an angle of 45° and a corner radius of 5 mm. The operating time of each instrument until fracture was measured and the number of cycles to fracture (NCF) calculated. Results ProTaper Next instruments showed greater resistance to cyclic fatigue compared to ProTaper Universal. The NCF value was significantly higher in ProTaper Next (1,296.83±20.2) instruments (p<0.001). The average length of fractured fragments was statistically significantly higher in ProTaper Universal (4.52±0.33) instruments compared to ProTaper Next (3.82±0.27) (p<0.001). Conclusion It was concluded that the cyclic fatigue resistance of ProTaper Next instruments was higher compared to ProTaper Universal instruments

The effect of herbal extract Foeniculum vulgare Mill. solution on the mechanical and wetting properties of heat polymerized denture base resin

Introduction. Commercially used chemical dental cleansers adversely affect mechanical properties of denture. Therefore, there is a need for finding an alternative which will not change the surface properties of material. Aim. This paper studied the effect of the herbal extract (Foeniculum vulgare Mill.) solution on the wetting and mechanical properties of heat-polymerized denture base resin compared to the same properties of the same resin in the native state (in air) and exposed only to aqueous environment. Material and methods. Rectangular shape of heat polymerized acrylic resin (15 mm x 15 mm x 3 mm) were prepared and divided into: (i) sample continuously exposed to air - AIR; (ii) sample continuously exposed to distilled water - DW; and (iii) sample exposed to 10% solution of the fennel leaves extract - PES. Wetting properties were measured by sessile drop method, whereas mechanical properties were analyzed by nanoindentation method. Results. Results showed that samples AIR had the lowest ΘC value 64.5±2.3 °, while the other two samples DW and PES had similar ΘC values (75.4±3.3 °, 75.7±4.7 °, respectively). Furthermore, there was no statistically significant difference in hardness coefficient, while Young's modulus showed a significant difference (p < 0.005) only between the samples AIR and DW. Conclusion. The obtained values confirmed that fennel extract can be used as successful and efficient cleanser, without degradation of denture surface

Cyclic fatigue testing of ProTaper Universal and ProTaper Next rotary instruments of different diameters

Introduction Sudden fracture of instruments without previous warning signs, which occurs due to cyclic and torsional fatigue, represents the biggest problem and one of the most difficult complications during endodontic therapy. The aim of this research was to check the influence of diameter of the instruments on the appearance of cyclic fatigue in simulated canals in full rotation. Material and Method The study analyzed 24 ProTaper Universal instruments (12 instruments with a diameter of 25 and 12 instruments with a diameter of 30) and 24 ProTaper Next instruments (12 instruments with a diameter of 25 and 12 instruments with a diameter of 30). The instruments were tested in an artificial canal stuffed in a metal block at an angle of 45° and a corner radius of 5 mm. The operating time of each instrument until fracture was measured, and then the number of cycles to fracture (NCF) was calculated. The length of the fractured fragments (FL) was measured with a Vernier caliper. Results The number of cycles to fracture was higher (p < 0.001) in instruments of the ProTaper Universal group of diameter 25 (367.83 ± 17.00) compared to instruments of diameter 30 (329.33 ± 12.86) of the same group. The number of cycles leading to the fracture in instruments of the ProTaper Next group of diameter 25 (1189.33 ± 18.97) was higher (p < 0.001) compared to instruments of the same group of diameter 30 (971.08 ± 15.26). Conclusion Obtained results indicated that with an increase in the diameter of rotating endodontic instruments, there is a decrease in the resistance to cyclic fatigue

Anthropometric parameters and aesthetics in the making of fixed prosthodontic restaurations: Part 2

Introduction: The role of aesthetic dentistry in the field of fixed dental prosthetics is to redesign the smile, which means not only the treatment on the teeth, but also the treatment of the surrounding soft tissues. Successful therapy can be achieved by establishing the harmony between the static (teeth, gingiva) and dynamic factors (lips, cheeks, mimic muscles) at rest and when performing various functions of the orofacial system. The aim: of the study was to analyze the parameters of the oral soft tissues (gingival health, gingival height, gingival zeniths, lip line and symmetry and balance of the dentition) that affect the aesthetics of fixed prosthodontic restorations. Literature data and clinical experience were used. Conclusion: Adherence to the described parameters is of great importance in the development of aesthetic and functional fixed prosthetic restoration

Comparison of the morphological parameters of the face in a population with a full dental arch

Introduction: The analysis of facial parameters in young people with a full dental arch is an assessment of the representation of certain anthropological features in the Serbian geographical area, but also a starting point for their reconstruction after tooth loss in order to achieve the maximum therapeutic and aesthetic effect. Aim: The aim of the work was to measure and compare facial parameters among respondents with a complete dental arch. Material and methods: 91 dental students participated in the research, 32 (35.2%) male and 59 (64.8%) female. The average age of the respondents was 22.16±1.53 years. The length and width of the face were measured, as well as the vertical and horizontal parameters, and the facial index was calculated. Results: Men had a significantly longer (Z=4.567; p<0.001) and wider face (Z=5.962; p<0.001) compared to women. There was no significant difference in the face index between women and men (ch 2 =2.492; p=0.666). There was also no significant difference in the vertical analysis of the face according to gender (ch 2 =0.065; p=0.798). In the majority of subjects, the shorter middle third of the face was measured. In the case of the expected division of the lower third of the face, it exists in a significantly greater extent in males (ch 2 =5.989; p=0.014). In the majority of subjects, the intercanthal width corresponded to the width of the eye, in both sexes, without statistical significance. Further, in a significantly larger number of male and female respondents, it was determined that the bipupillary corresponds to the intercommissural distance. The interalar distance corresponding to the width of the eye was more significantly present in women (ch 2 =5.002; p=0.025). Conclusion: Measurement of facial parameters can significantly improve dental therapy by enabling optimal aesthetic performance

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives